For efficient modulation and error control coding, the deliberate flipping approach imposes the run-length-limited(RLL) constraint by bit error before recording. From the read side, a high coding rate limits the correcting capability of RLL bit error. In this paper, we study the low-density parity-check (LDPC) coding for RLL constrained recording system based on the Unequal Error Protection (UEP) coding scheme design. The UEP capability of irregular LDPC codes is used for recovering flipped bits. We provide an allocation technique to limit the occurrence of flipped bits on the bit with robust correction capability. In addition, we consider the signal labeling design to decrease the number of nearest neighbors to enhance the robust bit. We also apply the density evolution technique to the proposed system for evaluating the code performances. In addition, we utilize the EXIT characteristic to reveal the decoding behavior of the recommended code distribution. Finally, the optimization approach for the best distribution is proven by differential evolution for the proposed system.

翻译：为高效调制与差错控制编码，在记录前采用有意识翻转方法施加游程长度受限（RLL）约束。从读取端来看，高编码率限制了RLL比特差错的纠错能力。本文基于非等差错保护（UEP）编码方案设计，研究面向RLL约束记录系统的低密度奇偶校验（LDPC）编码。利用非规则LDPC码的UEP能力恢复翻转比特，提出一种分配技术将翻转比特限制在具有稳健纠错能力的比特位上。此外，通过信号标记设计减少最近邻数量以增强稳健比特，并应用密度进化技术评估所提系统的码字性能。同时利用EXIT特性揭示推荐码字分布的译码行为，最终通过差分进化证明所提系统最优分布的优化方法。